How to check out a used motor, especially for corrosion issues?

[1Lhorn]

I'm going to be checking out a boat with an approx 15 yo motor. I've seen the motor and is looks only lightly used but who can tell by appearances. Since we live near brackish water I'm a bit concerned that perhaps the boat could have been used without proper flushing and could have corrosion issues. Other than having the owner start the motor, any other basic things I should look for to help make sure I'm not buying a motor with hidden problems? Are there things that would be tell tail signs of salt water use or improper maintenance?

I have no idea how this works, but thought that I would pay the owner for the boat but make them sign a informal contract that says I have the right to a full refund if I find any issues with the boat for a period of 1 week.

I have done compression checks on auto motors so I think I could do this on a marine outboard.


Any advice on checking out a used motor is greatly appreciated.
Thanks

 

[Frank Acampora]

Re: How to check out a used motor, especially for corrosion issues?

Your idea of a contract is a good one except that no seller will go for it--at least no seller in his right mind... But you can try!

Look at the general condition of the boat--If the owner did not care for it, he certainly will not have flushed the engine. If it is an outboard engine, take off the cover and look closely at the block. If there are corrosion issues, a lot of times it will show white crusting at the edges of gaskets, especially the exhaust cover gaskets. Sometimes you will also see rust on the head bolts.

DEFINITELY look at the condition of any anodes. If they look deeply pitted and crumbly, there has been more than occasional brackish/salt water usage. Pay close attention to the condition of the lower unit.

 

[TD_Maker]

Re: How to check out a used motor, especially for corrosion issues?

I also live on salt water, so I am used to looking at salt-water motors. First, look for corrosion around the mounting bracket. Also, tilt the motor up and look for corrosion around the trim and tilt unit. Often this area is missed when you spray the salt off the outside. Fittings may have missing paint, or even rust on some motors. Look for a whitish powdered salt coating in these areas.

Pull the hood. Does it look clean? Is the same whitish coating covering parts of the motor? Paint bubbling or peeling? Pull a plug wire and look at the plug itself. Is there rust around the edges? How about the flywheel? Rusty?

My point is that any boat owner who operates on or near salt water will use W-40 (or similar) liberally on the inside of the motor. It quickly becomes your best friend. If under the hood is bone dry, then you have your answer if SALT WATER maintenance was regularly used.

 

[1Lhorn]

Re: How to check out a used motor, especially for corrosion issues?

Thanks a million for the replies. I already looked under the cover and it's really clean. I'll check the anodes. Gotta figure out where they are and what they look like. Lol.

The boat is well kept, but I will give it a real close inspection as you've suggested.
You don't think a seller would let me get it checked out by a professional shop? Maybe the whole idea of the contact is not necessary, but I recently ran into a deal with a scumbag so it's made me extra careful about protecting myself.

Are there any online resources for people with little to no knowledge (such as myself) who are interested in routine outboard maintenance, like oil changes, flushing, lubricating, etc.

Edit - nevermind. Found some stuff on youtube

Thanks so much for your replies.

 

[pckeen]

Re: How to check out a used motor, especially for corrosion issues?

Your idea of a contract is a good one except that no seller will go for it--at least no seller in his right mind... But you can try!

I don't know Frank - I've given a contract like this before...with a car I sold to a local kid. I valued the good relationship over the $$$ for the car.

 

[dingbat]

Re: How to check out a used motor, especially for corrosion issues?

Rust on bolt heads, bubbled paint, etc. is superfisual and expected on salt run outboards no matter how it was cared for. The only way you can tell the real condition is to pull the heads and check the condition of the cooling passages.

A 15 yro salt run motor is pushing the life expectancy pretty hard if run regularly

 

[Sea Rider]

Re: How to check out a used motor, especially for corrosion issues?

Which HP and brand is that engine ? You could be buying an unopened pandora box which was conveniently been through a make up process to sell it, all enters through the eye. You could have a maniac owner rinsing water after each outing but has never done a exhaustive fresh water flush specially on enginess that needs to be flushed with engine on for thermo to open and achieve a correcct water flush through the whole cooling water pasages. Will agreed with Dingbat that the only way to check crankase internal cond is to remove cylindr head along all water lids and check its salty or non salty paassages conditions.

An engine that has clean water passages will cool crankcase better and achievet better overall performance and be more responsivenes throughout the whole throttle range than the one which doesn't. Years back bought a EVI 15 in mint looking external and internal cond, just to find out some time after due to an algae overhest and new head gasket, that owner didn't know a thing about flushing engine with fresh water. Was completely over salted.

It's not a great idea to spray an overdose of W40 liberally. All greased parts that slides or rotates will be washed away and sometimes will need to be disasssembled to be correctly greased again, much better is to spray small amounts of W40 on a small brush and fully "paint" crankcase and surrounding areas. Reapply as needed. Will have less W40 spills along looooong can duration.

Happy Boating

 

[1Lhorn]

Re: How to check out a used motor, especially for corrosion issues?

The motor is a 25hp Mercury Bigfoot. The seller is the daughter of the original owner. Her story is that the boat was purchased new in 1999. Father used it for 3 years then he passed away. She and her husband kept it under tarps all year except took it out in a freshwater lake once a year at a family gathering. While her father had it, he mainly fished in a local reservoir or in the delta (which depending on where they fished is likely brackish). Other than some carpet wear on the deck in front of the motor, it shows very little wear. Seats are perfect, paint on the boat is very good. She says motor/boat have very low hours which is believable given it's condition. Boat comes with a small trolling motor but the son in law says the original owner didn't really troll. Just anchored or tied up to a tree overhanging the bank and fished and drank beer.
Motor looks extremely clean under the cover but I will check it out again based on some of the recommendations above. Will check the annode (figured out where this is located on youtube). I'll ask her what she knows about service records or mainenance. At the very least I'll ask them to hook it up to a water hose and briefly start the motor and I'll do a compression check.

Compared with other motors I've looked at, it's a fair bit newer and seems believable that it might be lowish hours. Considering where I live, any motor bought in this area is suspect for sater water or brackish water use.

Thanks as always for sharing your experience with a newbie.

 

[Sea Rider]

Re: How to check out a used motor, especially for corrosion issues?

Personally wouldn't be too much worried if used on blackish water as long it's not blackish salt water. Salt water is bad if not well flushed after use, which is ideal a must do. The best way to test an engine is going out and test it throughout idle, medium to wot throttle range and check its water performance.

Being an 15 year oldie probably will need new spark plugs and water pump specially if engine was used on blackish waters, There must be a trim tab anode under anticavitation plate and probably small round ones on swivel bracket. If worn or corroded from use which is quite normal, replace all anodes for new ones. If you go for it post your findings, just for the record.

Happy Boating

 

[1Lhorn]

Re: How to check out a used motor, especially for corrosion issues?

I'm sorry, I hope I used the term correctly but I meant brackish water. It's not straight salt water like the SF bay but it's not straight fresh water either.

 

[Sea Rider]

Re: How to check out a used motor, especially for corrosion issues?

I'm sorry, I hope I used the term correctly but I meant brackish water. It's not straight salt water like the SF bay but it's not straight fresh water either.

Anyway, for that matter blackish water will form less salt layers inside cooling water passages, than blackish salty waters in the event engine was not flushed properly after use. As been said before, it's impossible to know for sure how much salt layers has already been formed inside cranckase without removing cylinder head to have an interior look.

Happy Boating